1. Field of the Invention
The present invention relates generally to bicycle steering head apparatus and specifically to an improved moisture sealed headset for use therewith.
2. Description of the Prior Art
A bicycle is typically provided with steering head apparatus to allow steering by rotation of the front wheel about a steering axis defined by a head tube mounted to the frame of the bicycle. In such a typical bicycle, the axle of the front wheel is attached to a front fork assembly which includes a fork tube which can rotate within the head tube.
A ball bearing headset is also typically provided to minimize friction between the head tube and the fork tube. This ball bearing headset includes lower and upper headset assemblies which position the fork tube with respect to the head tube while allowing rotation of the fork tube and the attached front fork about the steering axis. Both the lower and upper headset assemblies include ball bearings to minimize friction. To function properly, the headset must be capable of transferring weight from the frame of the bicycle to the front fork while allowing the front fork to rotate freely about the steering axis. By virtue of their mounting location in the front of bicycles, headsets are exposed to a range of dust, dirt and moisture. In prior art headsets, these ball bearings are not sealed, thus bearing failures due to dust and dirt contamination and corrosion are common.
What is needed, therefore, is a headset with a seal for the ball bearing thereby increasing service life of the headset.
In my copending application a seal was located exteriorilly of, and below the ball bearing for both the lower and upper headset assemblies. With respect to the lower headset assembly, the position of the seal was effective in minimizing the adverse effects caused by the presence of dirt, dust and moisture. However, the upper part of the upper assembly was not sealed. Thus, dirt, dust and moisture could enter and adversely affect operation of the upper headset assembly.
A primary object of this invention is to provide a bicycle headset that will operate reliably under road conditions characterized by dust, dirt and moisture.
An additional object of this invention is to provide a bicycle headset having ball bearings that are isolated from the external environment by a seal.
These and other objects, which will become apparent, are accomplished in accordance with the illustrated preferred embodiment of this invention by providing an improved bicycle headset having ball bearings with O-ring seals to protect those ball bearings against contamination.